This invention relates to tennis and other game rackets, and in particular to devices used in stringing such rackets.
Conventional tennis rackets are generally strung in a string network having a rectangular grid pattern, using the "basketweave" or some minor variation of the basketweave. Generally, a long string is used with a string support so that the string passes back and forth across the racket face to form the various strings in the pattern. There are many well-known stringing machines which are used to aid in such stringing of rackets. With these machines, the racket to be strung is held firmly in the machine. When the operator threads a string across the racket head, that string is held in tension until it is either tied off or held in tension by the tensioning of the next string in the network. Typically, this tensioning is achieved by one of two different methods.
The first string tensioning method involves the use of a "one-string" clamp which is attached to the racket stringing machine. The one-string clamp includes a "mouth" defined by a single set of "jaws" which may be selectively closed about a string-to-be-held-in-tension. The one-string clamp is adapted so that it may be simultaneously clamped tightly to the string-to-be-held-in-tension, and to the racket stringing machine. Thus, with the racket held firmly in the machine and the string held tightly to the machine, the string is held tight with regard to the racket. An exemplary form of such a stringing machine (having a one-string clamp, is the Model Serrano 6000, manufactured by Tennis Machines Inc., St. Louis, Mo.
The second conventional string tensioning method involves the use of a "two-string" clamp. The two-string clamp generally includes two mouths and two pairs of jaws. In use, the jaws of one mouth are clamped onto a first string which is already firmly held under tension and the jaws of the second mouth are clamped onto the new string-to-be-held-in-tension. In this case the clamp has no attachment to the racket stringing machine and the new string is held in position with regard to the racket because the previously tensioned string is holding the clamp in position with regard to the racket. An exemplary form of such a two-string clamp is the Model Century Superclamp, distributed by Century Sports, Plainfield, Mo.
The one-and two-string clamps used with the conventional grid string pattern have teeth cut into the ends of the jaws to allow insertion into a partially strung grid without causing any interference with the strings that have already been inserted perpendicularly to the strings currently being clamped under tension.
While such clamps are well suited for use in stringing conventional ninety degree grid networks, the clamps may not be used to string the three or more direction oriented string networks disclosed in the incorporated reference. In one form of those networks (having three string sets), the various strings-to-be-held-in-tension intersect at sixty and one hundred twenty degrees from the new strings being tensioned and clamped. Thus, the cut of the teeth of the clamps designed for the grid pattern cannot be used to clamp the new strings being inserted into a three direction strung racket.
Accordingly, it is the primary object of the present invention to provide a "one-string" clamp with teeth designed to be inserted into a three or more direction strung network and to hold a new string under tension until it can be tied off or until the next string can be placed under tension.
It is another object of the invention to provide a "two-string" clamp with teeth designed to be inserted into a three or more direction strung network and to hold a new string under tension until it can be tied off or until the next string can be placed under tension.